Research suggests that children's behavioral trajectories are influenced by the behavioral climates of their elementary schools, and that the quality of school and classroom environments may have long-lasting effects on behavioral outcomes in adolescence and adulthood. Moreover, several interventions to improve the behavioral climate of schools have demonstrated efficacy, while other promising approaches are currently being evaluated. Additional information about the effects of school behavioral climate in naturalistic settings is needed, however, in order to evaluate the potential demand for school intervention programs nationwide. In particular, there have been few studies of the current quality of elementary school environments in the U.S., and few attempts to estimate the effects of school behavioral climate on child behavior using non-experimental data. Also, several limitations in study design and scope apply to the existing literature. This proposed study will begin to address these limitations by estimating models of the quality of elementary school's behavioral climates, and models of the effects of behavioral climate on childhood behavior problems using data from a nationally-representative, non-experimental, longitudinal study of kindergartners. The specific aims of this study are: 1) to estimate the proportion of elementary schools in the U.S. with disruptive learning environments; 2) to identify elementary school and teacher characteristics that are significantly associated with the disruptiveness of classrooms and with school climate; and 3) to estimate the effects of children's school environments on the persistence of behavior problems from kindergarten through third grade. The data will come from the Early Childhood Longitudinal Study -- Kindergarten Cohort (ECLS-K), a longitudinal study of approximately 22,000 children attending kindergarten at baseline. Effects of school climate on child behavior will be estimated using multilevel models that allow for interactions between school climate and behavior problems at baseline. The study will provide a more comprehensive picture of the status of schools and their effects on child behavior than has been available previously.